Previous studies have suggested the use of digester biogas mixing systems for in situ ammonia removal from anaerobic digestates. The feasibility of this was tested at moderate and complete gas mixing rates at mesophilic and thermophilic temperatures in a 75-L digester. Experimental results showed that at gas mixing rates typical of full-scale commercial digesters the reduction in total ammonia nitrogen concentrations would be insufficient to allow stable acetoclastic methanogenesis in mesophilic conditions, or to prevent total inhibition of methanogenic activity in thermophilic food waste digestion. Simulation based on batch column stripping experiments at 55°C at gas violent flow rates of 0.032 m m min indicated that ammonia concentrations could be reduced below inhibitory values in thermophilic food waste digestion for organic loading rates of up to 6 kg VS m day. These mixing rates are far in excess of those used in full-scale gas-mixed digesters and may not be operationally or commercially feasible.
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http://dx.doi.org/10.1080/09593330.2017.1291761 | DOI Listing |
Sci Rep
January 2025
School of Earth Sciences, China University of Geosciences, Wuhan, 430074, Hubei, China.
Soil magnetic records in Quaternary red earth (QRE) deposits contain a valuable record of paleoclimate information, providing insights into controls on Earth's climate system in the past and potentially helping to predict its response to perturbations in the future. Here, analysis of the environmental magnetism and mineralogy of the Xuancheng QRE (Anhui Province, South China) shows that magnetic variation was strongly linked to production of authigenic ferrimagnetic minerals such as maghemite. Fine-grained maghemite formed during the weathering-related transformation of iron-bearing illite to vermiculite, generating aggregates of vermiculite or mixed-layer illite-vermiculite.
View Article and Find Full Text PDFOn August 24, 2023, Japan controversially decided to discharge nuclear wastewater from the Fukushima Daiichi Nuclear Power Plant into the ocean, initiating intense domestic and global debates. This study employs a mixed-method approach, integrating quantitative evolutionary game theory and qualitative data analysis to explore the strategic dynamics among Japan, other nations, and the Japan Fisheries Association regarding this decision. The data includes international environmental reports and economic statistics, served as the basis for simulating decision-making processes under various legal, economic, and environmental pressures.
View Article and Find Full Text PDFJ Sci Food Agric
January 2025
College of Food Science and Engineering, South China University of Technology, Guangzhou, China.
Background: Polyether ether ketone (PEEK) was modified by a sulfuric and nitric acid mixed system to improve the solubility of the material and the gas selective permeability of the film. SN1 and SN5, synthesized from mixed acid systems (with ratios of nitric acid and sulfuric acid of 1:1 and 1:5, respectively) were chosen because they had comparable nitro groups but differing sulfonyl groups. To investigate the impact of the type and content of sulfonated and nitrated polyether ether ketone (SNPEEK) on the structure and physicochemical properties of the films, SN1/polyvinyl chloride (PVC) and SN5/polyvinyl chloride films were made by adding varying amounts of SN1 and SN5 (0.
View Article and Find Full Text PDFBackground: Household air pollution is a major contributor to cardiovascular disease burden in women in Sub-Saharan Africa. However, little is known about exposures during pregnancy or the effect of clean cooking interventions on postpartum blood pressure trajectories.
Methods: The Ghana Randomized Air Pollution and Health Study (GRAPHS) randomized 1414 non-smoking women in the first and second trimesters to liquefied petroleum gas (LPG) or improved biomass stoves - vs control (traditional three-stone open fire).
Heliyon
January 2025
Department of Mechanical Engineering, Addis Ababa Science and Technology University, Addis Ababa, 16417, Ethiopia.
Many approaches have been implemented in order to reduce the emissions of particular pollutants without compromising engine performance. Cotton and castor mixed seed oil was chosen for the current study due to their distinct fatty acid composition and potential as a feedstock for bio-additives. Three fuel samples-99 % diesel and 1 % blended fuel (cottonseed oil + castor seed oil), 99.
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